Bisphenol A epoxy resins obtained by reacting epichlorohydrin with bisphenol A have conventionally been used extensively as general-purpose epoxy resins in applications such as coating materials, electrical insulating materials, laminates, structural materials, etc. However, the bisphenol type epoxy resins have insufficient weatherability because they have aromatic rings. For use in applications where weatherability is especially required, compounds obtained by epoxidizing cyclohexene type alicyclic olefins with peracetic acid are commercially available as weatherable epoxy compounds.
On the other hand, in place of the epoxidation with peracetic acid, various proposals have conventionally been made on attempts to hydrogenate the aromatic rings of a bisphenol type epoxy resin to produce the corresponding alicyclic epoxy resin. In this nucleus hydrogenation, epoxy group decomposition should be minimized.
For example, U.S. Pat. No. 3,336,241 or JP-A-10-204002 (the term "JP-A" as used herein means an "unexamined published Japanese patent application") proposes a method in which an organic compound having at least one vic-1,2-epoxy group and at least one C--C double bond is hydrogenated using a catalyst comprising rhodium or ruthenium supported on active carbon. In U.S. Pat. No. 4,847,394 and JP-A-8-53370 is proposed a method in which a homogeneous ruthenium catalyst obtained through reduction with a compound having a specific oxidation-reduction potential is used.
However, the former method has problems that the catalytic activity is low and a considerable proportion of the epoxy groups are hydrogenated and decomposed. In addition, the active carbon used is a support having a large specific surface area. The latter method, although excellent in catalytic activity and selectivity, has problems concerning catalyst recovery and reuse because it is not a support-based catalyst and, hence, the ruthenium, which is expensive, is difficult to be completely separated from the reaction product.